1. Field of the Invention
Exemplary embodiments of the present invention relate to a photoresist composition and a method of forming a pattern by using the photoresist composition, and more particularly, to a photoresist composition that may be used to form a photoresist pattern having a high profile angle and a method of forming a pattern by using the photoresist composition.
2. Discussion of the Background
In a process of manufacturing printed circuit boards, semiconductor wafers, and substrates of liquid crystal display (LCD) panels, a complicated circuit pattern is typically formed on a top surface of a base substrate such as an insulating substrate or a glass substrate. To form the circuit pattern, a photolithography technique is widely used.
According to the photolithography technique, a photoresist film is formed on a base substrate and is exposed to light by using a photomask that has a mask pattern that corresponds to a circuit pattern. Photomasks are manufactured with high precision and are very expensive. Thus, research is being conducted on a method of exposing a photoresist film to light by using a reduced number of photomasks or without using photomasks through process improvement.
As an example of an exposure method for photoresist films that does not use photomasks, a digital exposure method in which an exposure beam of light is digitally controlled to be turned on or off for each pixel of a mask pattern is receiving attention. In the digital exposure method, millions of micromirrors of a spatial light modulator are instantaneously driven to selectively reflect light emitted from a light source. Accordingly, light is spatially modulated and controlled to form a pattern on a substrate.
The digital exposure method may use light from an H-line laser diode instead of a conventional high-pressure mercury lamp in order to prevent the deterioration of digital micromirrors, which are typically aluminum. H-line light may have a wavelength of approximately 405 nm. To form a pattern having a high profile angle, i.e., an angle of the walls of the patterned structure that are nearly normal to the supporting structure, using the digital exposure method, a photoresist composition with high sensitivity to the H-line light should be developed.